Combined filling device and vent cut-off valve for electric storage cells

ABSTRACT

A combined filling device and vent cut-off valve for an electric storage cell having a tank with an electrolyte which is adapted to be replenished by distilled water. A stopper mounted on a cover plate is provided for closing the filling hole. The vent cut-off valve is effectively arranged between the space above the electrolyte in the tank and a vent provided in a cover plate and includes a valve member having a piston slidably mounted in a cylinder with a port and operative connected to the cover plate. When the stopper is in position in the filling hole, the valve member is in an open position in which the gas in the space above the electrolyte can escape to the atmosphere via the vent and when the stopper is removed from the filling hole the valve member is automatically closed to prevent the escape of gas to the atmosphere. The device can be mounted on the filling hole of any conventional battery by threaded bushings. The device is adapted for multi-compartment storage cells in which case the cover plate supports each stopper and is operatively connected to each cut-off valve.

[4 1 July 10, 1973 United States Patent 1 Rowe [ COMBINED FILLING DEVICEAND VENT Primary Examiner-Henry T. Klinksiek CUT-OFF VALVE FOR ELECTRICAttorney-Young & Thompson STORAGE CELLS [57] ABSTRACT A combined fillingdevice and vent cut-off valve for an [76] Inventor: Robert Arnold Rowe,17 Rue Chasseloup-Laubat, Paris (15 eme), France electric storage cellhaving a tank with an-electrolyte [22] Filed: 26,, 1971 which is adaptedto be replenished by distilled water. A stopper mounted on a cover plateis provided for PP 119,225 closing the filling hole. The vent cut-offvalve is effectively arranged between the space above the electrolyte inthe tank and a vent provided in a cover plate and in-' cludes a valvemember having a piston slidably mounted in a cylinder with a port andoperative ,con-

France 7007772 nected to the cover plate. When the stopper is in posi-137/587 b zf gg tion in the filling hole, the valve member is in an openposition'in which the gas in the space above the electrolyte can escapeto the atmosphere via the vent and when the stopper isremoved from thefilling hole the valve member is automatically closed to prevent theescape of gas to the atmosphere. The device can be mounted on thefilling hole of any conventional battery [58] Field ofSearch......................

v [56] References Cited UNITED STATES PATENTS by threaded bushings. Thedevice is adapted for multi- 2,603,672 7/1952 Reppert 136/177 3,508,9722,784,987 2,647,159

compartment storage cells in which case the cover 4/1970 Goldingay......

plate supports each stopper and is operatively connected to each cut-offvalve.

3/1957 Corcoran.......

7/1953 Lighton.....................::::......

11 Claims, 16 Drawing Figures .l VIII u 71/ PATENIED JUL 1 0791s FIG]snmiufa F/G.2 3 l if 190.6597 Amy 01.0 RO

COMBINED FILLING DEVICE AND VENT CUT-OFF VALVE FOR ELECTRIC STORAGECELLS The present invention relates to combined filling devices and ventcut-off valves for electric storage cells.

Such devices comprise an electric storage cell having a cover with atleast one filling opening and at least one vent hole for releasing gasformed in the cell, as well as a stopper for closing the opening andmeans for assuring the closure of the vent hole when the opening isunstopped. Such devices are used for example in lead batteries in whichlosses of water owing electrolytic decomposition are compensated byperiodic additions of distilled water.

In a known device the closure of the vent holeto prevent the escape ofgas when the filling opening is unstopped is assured by a swinging leadring or a displaceable ball which closes the vent hole when the stopperis withdrawn. Such a construction causes certain disadvantages, inparticular, the sealing provided is inadequate, and therefore the levelof the electrolyte in the battery can not be maintained substantiallyconstant.

ln other devices the battery is provided with a general cover with a capwhich oscillates along a shaft driving a rotary distributor whose lengthis such that it cooperates with all the compartments of amulti-compartment battery. Such devices lead to a complicatedconstructions necessitating a very high level of precision inconstruction in order to avoid jamming and provide adequate sealing.Some known devices neither enable the checking of the specific gravityof the electrolyte nor the emptying of the battery when necessary.

In other devices, the closure of the vent is effected by thedisplacement of a central sleeve located in the filling opening whichenables the opening of the vent holes when a cover plate element is inplace and their closure when the element is removed. This system has thedisadvantage of reducing the diameter of the filling opening, and thepresence of operating members in the filling orifice, however, can causethe downward displacement of a sliding portion operated from theexterior of the battery during the filling operation which may disablethe filling cut-off and thereby cause the overflow of electrolyte.

An aim of the present invention is to overcome the above-mentioneddisadvantages and to provide a combined filling device and vent cut-offvalve in which the vent for releasing gas can be closed in a fluidtightmanner in order to enablethe addition of liquid sufficient to return theelectrolyte to the desired level.

An aspect of the present invention consists in'a combined filling deviceand vent cut-off valve for an electric storage cell having a tank for anelectrolyte, a filling hole for replenishing the electrolyte and a ventallowing the escape of gas from the tank to the atmosphere, comprising astopper for the filling hole, said vent cut-off valve including a valvemember slidable mounted in a cylinder between a closed positionpreventing the escape of gas from the tank throughthe vent and an openposition permitting the escape of gas through the vent, operating meansfor simultaneously removing the stopper and the closing the valve andfor simultaneously re-inserting the stopper and re-opening the valve,and a detent for retaining the valve in its closed position until theoperating means brings the stopper into position in the filling hole.

A more particular aspect of the invention consists in a cover for thestorage cell comprising a vertical cylinder parallel to the filling holeand having a smooth inner wall and therefore can not grab onto an objectextending thereinto, the cylinder is provided with one or more portscorresponding to the volume in the tank above the electrolyte. Further,the cylinder is put into communication with the surrounding atmospherewhen a cover plate and the stopper are in position.

The valve member slidably arranged in the cylinder preferably comprisesa headportion, stop means for limiting the upward and downward movementsof the valve member, a piston having a diameter substantially equal tothat of the inner diameter of the cylinder out of contact with the portsin the cylinder in its normal position and covering over at least one ofthese ports during filling, means for maintaining the valve member inits closed position which is overcome by a force for releasing the valvemember, the stopper being fixed to means for returning the valve memberat its open position.

Further the device preferably comprises at least one of the followingfeatures means for limiting the upward movement of the valve memberincluding a stop shoulder having a cross-section greater than that ofthe rod on which the piston is supported cooperating with the endportion of the cylinder which has an aperture having a cross-sectionless than that of a disc at the end of the valve member remote from thehead portion ;the means for limiting the downward movement of the valvemember comprising-the lower face of the piston cooperating with the endportion of the cylinder the means for maintaining the valve member inits upper position comprising a detent on the lower portion of the rodremote from the head portion which is adapted to cooperate with a borehaving a cross-section such that a substantial force must be exerted inorder that the detent pass from one side to the other of the said borethe means for returning the valve member to its open position includingresilient arms adapted to engage under the shoulders formed by the headportion the stopper being fixed to a cover plate covering the valve andthe filling hole and having a vent for the escape of gas the cover platehaving on its lower face means for engaging the head portion of thevalve member for returning the same to its open position a guide tongueis provided on the piston slidable in a slot in the cylinder preferablyin the port in communication with the space above the liquid level inthe tank of storage cell the tank of the storage cell including aplurality of compartments and a plurality of stoppers mounted on acommon cover plate. 7

The present invention will now be described by way of example withreference to the accompanying drawings illustrating a combined fillingdevice and vent cutoff valve for electric storage cells in which FIG. 1shows a cross-section of one of the compartments of multi-compartmentelectric storage cell ac cording to the invention with the stopper inthe filling hole and the vent cut-off device in its open position FIG. 2shows a detail of the filling device and the cutoff valve shown in FIG.1 with the stopper out of engagement with the filling hole and thecut-off valve in its closed position FIG. 3 shows a top view of thestorage cell shown in FIG. 1 with the cover-plate removed therefrom FIG.4 shows a plan view of the underside of a cover plate illustratingseveral arrangements of resilient arms FIG. 5 shows an alternativeembodiment in section of the device according to the invention in aposition corresponding to FIG. 1

FIG. 6 shows the embodiment of FIG. 5 in the position corresponding toFIG. 2

FIG. 7 shows a further alternative embodiment in section in a positioncorresponding to FIG. 1

FIG. 8 shows the embodiment of FIG. 7 in a position corresponding toFIG. 2

FIG. 9 shows a still further embodiment of the device according to theinvention in a position corresponding to FIG. 1

FIG. 10 shows an elevation view with a cut away portion of the valvemember of the embodiment shown in FIG. 9

FIG. 10A shows a plan view of valve member of FIG. 10;

FIG. 11 shows a view in section of the embodiment shown in FIG. 9 in aposition corresponding to FIG. 2

FIG. 12 shows a view in section of a further alternative embodiment ofthe device according to the invention in a position corresponding toFIG. 1

FIG. 13 shows a view in section of the embodiment of FIG. 12 in aposition corresponding to FIG. 2

FIG. 14 shows a view in section of a still further embodiment of thedevice according to the invention and FIG. 15 shows a final alternativeembodiment of the device according to the invention.

FIG. 1 shows an electric storage cell having a tank 1 with a pluralityof juxtaposed compartments arranged perpendicular to one another onlyone of these compa'rtments is shown. A terminal 3 corresponds to thiscompartment of the cell an electrolyte 4 is provided in the tank 1. Afilling opening 5 is closed with a stopper 7 depending from a coverplate 6. Other stoppers 7 are shown in FIG. 4.

A valve member 8 for controlling the escape of gas comprises a rod witha conical head portion 9 which has an outer diameter greater than thesection of the rod immediately therebelow to which it is connected byshoulders 9a. Resilient arms 22, 23 depending from the cover plate 6have end portions engageable with the shoulders 9a of the head portion,the operation of which will be described in detail below. The valvemember 8 includes a piston 10 having a diameter substantially equal tothat of cylinder 13 in which it is arranged for sliding movement. Thelower surface of the piston 10 comes into abutting contact with a lowerend portion 18 of the cylinder 13 and the position of the valve member 8when the piston 10 is in abutting contact with the lower end portion 18defines the lower limit of the path of movement of the valve member.

Below the piston 10, valve member 8 includes a rod portion dependingfrom the piston 10 having a diameter less than that of the piston. Thelower rod section 11 is adapted to pass through a bore 19 provided inthe lower end portion 18 and a disc 12 is disposed at the end of the rodsection 1 1 and is adapted to abut against the lower face of the lowerend portion 18 and thereby defines the upperlimit of the path ofmovement of the valve member 8.

The cylinder 13 includes ports 14 formed as a slot for communicationwith the interior of the tank above the level of the electrolyte andslots 15 for communication with a groove 16 in the cover 2 arranged onthe tank 1. The groove 16 extends in the direction perpendicular to theplane of the FIG. 1 and is in communication with the surroundingatmosphere via vcnt 17 in the cover plate 6.

The bore 19 in the lower end portion 18 of the cylinder has a diameterslightly greater than that of the lower rod section 11. A detent isprovided on the rod section 11 in the form of a resilient lateral boss20 which upon the application of force can pass through the bore 19 butwhich in its FIG. 2 position maintains the valve in its closed position.

The piston 10 on the valve member 8 is provided with a lateral tongue 21which is slidable in a slot 14 and the combination thereof acts as ameans for guiding the valve member between its open and closedpositions.

In the position shown in FIG. 1, the filling opening 5 is closed by thestopper 7 and the space above the level of the electrolyte 4 is incommunication with the atmosphere through the intermediary of the slotor port 14, I

the interior of the cylinder above the upper section of the valve member8, the slot 15, the groove 16 in the tank cover 2 and finally throughthe vent hole 17 in the cover plate 6.

In the position of the device shown in FIG. 2, the cover plate 6 hasbeen moved upwards, and the stopper 7 was just come out of engagementwith the filling opening 5. The valve member 8 has been moved upwards bymeans of the resilient arms 22, 23 extending from the cover plate untilthe disc 12 on the valve member comes into contact with the lower endportion 18 of the cylinder. Upon the continued upward movement of thecover plate 6, the resilient arms move outwardly and out of engagementwith the shoulders as shown in FIG. 2. The piston 10 in FIG. 2 closesthe port 14 and thereby prevents the escape of gases while the valvemember is in its raised position. The valve memher is maintained in itsraised position in which the disc 12 is in contact with the lower endportion by means of the detent 20 which having passed through the bore19 comes into contact with the upper surface of the lower end portion 18of the cylinder.

The cover plate 6 and the stopper 7 can be completely removed bycontinuing the upward movement,

the resilient arms thus returning to their normal position and the valvemember being maintained in its raised position by the detent. Once thecover plate has been removed distilled water can then be poured into thetank through the filling hole 5. Since the gas present in the tank abovethe electrolyte 4 can not escape, the level to which the electrolyte canrise is thus limited by the pressure exerted by the gas. Accordingly,once the liquid in the tank has reached this level, it begins to rise inthe filling opening 5 thus indicating that the required level has beenreached. To close the cell, the cover plate 6 is put into position andthe stopper enters the filling hole. The water accumulated in theopening 5 seeks its own level as the space containing the captured gasabove the electrolyte is brought back into contact with the atmosphere.

FIG. 4 shows the underside of a cover plate 6 on which are mounted threedifferent arrangements of the resilient arms. In the first arrangementthe arms 22 comprise a pair of opposed resilient arms. In the nextarrangement, four flexible arms 23 are arranged at right angles relativeto one another such an arrangement is shown in FIGS. 1 and 2. In thefinal arrangement four flexible arms 24 are also at right angles to oneanother but the orientation relative to the cover plate is displacedthrough 45. It should be noted that the resilient arms on a given coverplate will normally all be of the same number and orientation. Finally,these examples are not considered all-inclusive.

In the embodiment shown in FIGS. 5 and 6, the disc 12 has been replacedby stop means arranged at upper limit of the path of movement of thepiston 10. The stop means comprises a cylindrical element 32 havingexternal screw threads which mount it in the body of the cell.Accordingly, as shown in FIG. 6, the piston of the valve member 8 comesto abut against the stop member 32 to define the upper limit of the pathof movement of the valve member. The operation is the same as that shownin the embodiment of FIGS. 13.

The embodiment of FIGS. 7 and 8 employs the same type of upper limitstop means 32 as shown in the previous embodiment. The guiding tongue aswell as the slots 14 and 15 have been eliminated in this embodiment.Instead of the slots, a hole 33 is provided in the wall of the cylinderthrough which gas may pass from the tank to the vent 17 through the samepassage-way as described above. In its raised position the piston 10seals off the port 33 thus preventing the escape of gas.

FIGS. 9-10 show a further alternative embodiment in which the valvemember 34 and the means for raising the valve member to the closedposition are different. In this embodiment the valve member is providedwith resilient arms 39 engageable with a male portion depending from thecover plate 6. FIG. 9 shows the position enabling the escape of gas fromthe tank the gas passes through the port 33, then through an annulargroove 35, a passage 38 running upwards between the arms and the venthole. Stop means for limiting movement is provided by a collar 36engageable with a shoulder formed by the cylinder to define the lowerlimit and a threaded sleeve 37 to define the upper limit of movement.The piston portion 44 of the valve member seals off the port 33 in theraised position as shown in FIG. 11. The valve member is maintained inits closed position by the detent portions 41 and 42 provided on theresilient arms 39 and 40 respectively. The lower end portion of thecylinder is provided with a bore 45 in order to alleviate theback-pressure which may be produced in returning the valve member to itsclosed position.

In the embodiment of FIGS. '12 and 13 which is similar to that of FIGS.7 and 8 but in which the valve member includes an intermediate enlargedsection 46 spaced from the piston 10, the intermediate enlarged sectionis arranged so that its lower surface is substantially in alignment withthe top of the port 33. in the open position as-shown in FIG. 12. Inthis position the gas can escape from the tank to the atmosphere passingthrough the port 33, vertical passages 47 provided in the intermediateenlarged section 46 and upwards to the vent hole 17. In the closedposition shown in FIG.

13 the port 33 is blocked by the piston 33 thereby preventing the escapeof gas during the filling operation.

It should be noted that the intermediate enlarged section 46 is formedof flexible material and has a diameter slightly greater than thecylinder. In FIG. 12 the section 46 is compressed. In FIG. 13, the upperportion of the intermediate section 46 extends beyond the inner wall ofthe cylinder and acts as a detent to maintain the valve member in itsclosed position until a force is exerted thereon to return the valvemember to its open position as shown in FIG. 12.

FIG. 14 shows a further variation of the invention which concerns, inparticular, the cover 52 for the tank. In the embodiment of FIG. 14, themoulded cover comprises a vertical sleeve 50 connected to the interiorof the vent valve mechanism by a channel 48 and by a vertical passage 49partially delimited by a sleeve 50 extending along the cylinder 15. Thecover plate 51 is formed of a semi-rigid material, such as polythene,and includes depending resilient arms and stoppers. The entire coverplate 51 with the stopper and the resilient arms is preferably mouldedas a unitary body. This embodiment operates in exactly the same way asthose of FIGS. 1-13, described above. The valve member is the same asthat shown in FIGS. 12 and 13. Any of the other valve members describedabove may be used instead of the one illustrated herein.

In the present embodiment and in the following embodiment theorientation of the cut-offvalve and the filling hole are different,i.e., instead of the arrangemnt shown in FIG. 3 they are aligned along asingle axis rather than the two axes shown in FIG. 3.

FIG. 15 shown a final preferred embodiment of the device according tothe invention. Unlike the previous embodiments the present embodiment isadapted to be used on a conventional battery such as those commonly inuse. To this end the screw-threaded filling holes of the battery whichare normally adapted to receive the screw-threaded plugs are in thepresent embodiment adapted to receive the combination according to theinvention. 1

In this embodiment the tank cover 52 has conventionally screw-threadedfilling hole 53 which is adapted to receive a cooperatively threadedbushing 54 which in turn supports therein a sleeve 50 secured thereto inany suitable manner, for example, by force fitting. The bushing 54 hasan outwardly extending flange 55 at its upper end. Between the sleeve 53forming the filling hole and the flange 55 are clamped a support plate57, a sealing member 58 and a unitary plate member 59 which is common toall of the compartments of the batteryonly one of which is shown. Thesupport plate 57 is provided with a horizontal passage 48 as in thepreceding embodiment.

Functionally the vent cut-off valve is the same as that of FIGS. 12-14.However, in this embodiment the cylinder 61 is threadedly connected tothe upper limit stop means 62. The entire combination formed of thefilling device and vent cut-off valve is effectively supported on thescrew-threaded filling hole 53.

Instead of the integral cover plate structure shown in the previousembodiments the cover plate 56 cooperates with a stopper having twopieces 70,71. The cylindrical portion has a flange engageable with theunderside of the cover plate 56 and external screw threads at its upperend. The screw threaded nut 71 has vents 71a therethrough and internalscrew threads which cooperate with the threads on the cylinder 70. Theresilient arms 23 are connected to an annular externally threadedelement 72. A threaded nut 73 is in cooperative engagement with theelement 72, the cover plate 56 is sandwiched therebetween. It is noted,however, that the threaded elements for the cover plate of the presentembodiment could be replaced with the integral construction of thepreceding embodiments.

The piston 10 is provided with a channel 75 extending from the bottom ofthe piston and in communication with the passageway to the vent holeabove the intermediate enlarged section 47 to enable the release of gasunder pressure trapped between the piston and the cylinder.

Needless to say there are various possible modifications of the devicedescribed herein falling within the scope of the invention in particularcertain elements could be replaced by their equivalents. For example,the means which limit the path of travel of the valve member in thecylinder could be provided on the cylinder or on the valve member and/orat different levels.

What I claim is:

l. A combined filling device and vent cut-off valve for an electricstorage cell having a plurality of compartments each containingelectrolyte, a filling hole for replenishing the electrolyte, and a ventallowing the escape of gas from the compartments to the atmosphere,comprising a plurality of stoppers, each stopper being engageable withan associated said filling hole, a plurality of vent cutoff valves, eachvent cut-off valve being disposed between a space above the electrolytein an associated said compartment and an associated said vent, each saidvalve including a valve member axially slidably mounted in a cylinderwhose axis is parallel to and spaced from the axis of the associatedfilling hole, and a port extending through the wall of said cylinder,each port being in communication with the space above the electrolyteand its associated vent, each valve member having a first position inwhich its associated port is open and a second position in which saidassociated port is closed, an operating member for inserting andremoving all the stoppers from their filling holes and forsimultaneously opening and closing all the valves respectively, anddetent means for positively retaining each valve in said second positionuntil said operating member brings the stoppers into position in thefilling holes.

2. A device according to claim 1, wherein stop means are provided forlimiting the movement of the valve member between said firstposition andsaid second position.

3. A device according to claim 2, wherein one stop means is mounted atthe upper end of the cylinder, and wherein another stop means is formedby the lower end of the cylinder.

4. A device according to claim 3, wherein a disc is' provided at thelower end of the valve member cooperating with the lower stop means insaid second position.

5. A device according to claim 1, wherein the valve member includes apiston mounted on a rod for movement in the cylinder, the diameter ofthe piston being substantially equal to the interior diameter of thecylinder.

6. A device according to claim 5, wherein a portion of the rod dependsfrom the piston, the detent being mounted on said portion of the rod andwherein the lower end of the cylinder has a bore whose diameter isgreater than that of said portion of the rod but less than the effectivediameter of the rod portion at the detent.

7. A device according to claim 5, wherein the detent means comprises anenlarged section disposed above the piston and spaced therefrom saidenlarged section being formed of resilient material which is compressedby the cylinder in the first position and is adapted to expand in aspace disposed above the cylinder in the second position for maintainingthe valve member in said second position.

8. A device according to claim 1, wherein the operating means comprisesa cover plate on which is supported said stopper and means engageablewith the valve member, and wherein the vent is arranged in the.

cover plate.

9. A device according to claim 1, further comprising means releasablyconnecting the operating means to the valve member includinga headportion defining shoulders and resilient arms releasably engageable withthe shoulders. I

10. A device according to claim 1, wherein a tongue is provided on thepiston adapted to cooperate in the port which is formed as a verticalslot in the cylinder for guiding the valve member between said first andsecond positions.

11. A device according to claim 1, wherein the filling hole isinternally threaded and further comprising an externally threadedbushing on which the vent cut-off valve is supported and in which ispositioned a sleeve the stopper being cooperatively engageable with saidsleeve.

* i I t

1. A combined filling device and vent cut-off valve for an electricstorage cell having a plurality of compartments each containingelectrolyte, a filling hole for replenishing the electrolyte, and a ventallowing the escape of gas from the compartments to the atmosphere,comprising a plurality of stoppers, each stopper being engageable withan associated said filling hole, a plurality of vent cut-off valves,each vent cutoff valve being disposed between a space above theelectrolyte in an associated said compartment and an associated saidvent, each said valve including a valve member axially slidably mountedin a cylinder whose axis is parallel to and spaced from the axis of theassociated filling hole, and a port extending through the wall of saidcylinder, each port being in communication with the space above theelectrolyte and its associated vent, each valve member having a firstposition in which its associated port is open and a second position inwhich said associated port is closed, an operating member for insertingand removing all the stoppers from their filling holes and forsimultaneously opening and closing all the valves respectively, anddetent means for positively retaining each valve in said second positionuntil said operating member brings the stoppers into position in thefilling holes.
 2. A device according to claim 1, wherein stop means areprovided for limiting the movement of the valve member between saidfirst position and said second position.
 3. A device according to claim2, wherein one stop means is mounted at the upper end of the cylinder,and wherein another stop means is formed by the lower end of thecylinder.
 4. A device according to claim 3, wherein a disc is providedat the lower end of the valve member cooperating with the lower stopmeans in said second position.
 5. A device according to claim 1, whereinthe valve member includes a piston mounted on a rod for movement in thecylinder, the diameter of the piston being substantially equal to theinterior diameter of the cylinder.
 6. A device according to claim 5,wherein a portion of the rod depends from the piston, the detent beingmounted on said portion of the rod and wherein the lower end of thecylinder has a bore whose diameter is greater than that of said portionof the rod but less than the effective diameter of the rod portion atthe detent.
 7. A device according to claim 5, wherein the detent meanscomprises an enlarged section disposed above the piston and spacedtherefrom said enlarged section being formed of resilient material whichis compressed by the cylinder in the first position and is adapted toexpand in a space disposed above the cylinder in the second position formaintaining the valve member in said second position.
 8. A deviceaccording to claim 1, wherein the operating means comprises a coverplate on which is supported said stopper and means engageable with thevalve member, and wherein the vent is arranged in the cover plate.
 9. Adevice according to claim 1, further comprising means releasablyconnecting the operating means to the valve member including a headportion defining shoulders and resilient arms releasably engageable withthe shoulders.
 10. A device according to claim 1, wherein a tongue isprovided on the piston adapted to cooperate in the port which is formedas a vertical slot in the cylinder for guiding the valve member betweensaid first and second positions.
 11. A device according to claim 1,wherein the filling hole is internally threaded and further comprisingan externally threaded bushing on which the vent cut-off valve issupported and in which is positioned a sleeve the stopper beingcooperatively engageable with said sleeve.